Luther Davis, 61, covers himself in several donated blankets as he wraps himself up to protect himself from the cold. Temperatures in New Orleans will reach into the low 30s. Davis is homeless and living on the street near Claiborne and Canal streets in downtown New Orleans.

By Leslie Williams and Mark Schleifstein Staff writers

Cold, dry arctic air that drove temperatures overnight into the upper 20s south of Lake Pontchartrain and to just below 20 in Slidell will continue to keep the New Orleans area chilly today.

A freeze warning in New Orleans overnight prompted a third straight night for the city's freeze plan, allowing homeless people to stay in a variety of shelters for free.

But many homeless braved the falling temperatures on city streets as sunset approached Wednesday, including a group who have set up camp on a stretch of asphalt under the overpass at Claiborne Avenue and Canal Street.

James Knight, 55, said passers-by had dropped off plenty of blankets, clothes and food to the dozens of people living under the overpass. Knight, who wore a winter hat that covered his ears, said his tent had more than four blankets inside.

"I'm not worried about the cold," he said. "I've got enough stuff to keep me warm."

Otis North, 50, agreed.

North has two beds on the concrete below the overpass.

"One for me and one for when I have company," he said.

He said he slept like a baby Tuesday night when it was cold and expected to do the same Wednesday night. North said he would rather not stay in one of the city-recommended shelters for the homeless.

"I have more control over things here," North said.

Mog Phan, 49, a native of Vietnam who said he was living in eastern New Orleans before moving to the Canal and Claiborne intersection, said he had a sleeping bag, a hat and coat.

"I'm not worried," he said.

James Haley, 49, said he moved from Fort Worth, Texas, to New Orleans about a year ago looking for work. He plans to leave the overpass today to begin work in the Gentilly area.

Haley, too, was unconcerned about freezing temperatures.

"I have a beautiful sleeping bag people gave me," Haley said. "I woke up this morning in it sweating."

With high temperatures expected to reach only the upper 40s this afternoon, expect the thermometer to hover early Thursday just above freezing on the south shore, and to dip into the upper 20s on the north shore and to the west of Lakes Pontchartrain and Maurepas.

In New Orleans, 10-mph winds overnight will make it seem as if the temperature is closer to 21 and probably will trigger the city's freeze plan again for a fourth night.

The cold air is accompanied by unusually high barometric pressure -- near 30.8 inches, or close to the 31-inch top of scale on most home barometers, said Tim Destri, a meteorologist at the National Weather Service's Slidell office.

Humidity rates also are dramatically low, between 20 percent and 30 percent on Tuesday and today.

That's low enough for forecasters to ask people in north shore communities to avoid outdoor burning, although the area received about 2 inches of rain during the past two weeks, Destri said.

While the low temperatures overnight Tuesday and tonight are the coldest experienced in the area in several years, they don't break records, Destri said. The Jan. 3 record for Louis Armstrong International Airport is 23, set in 1979, while the record at Audubon Park is 21 in 1887.

In Slidell, where records date back only to 1956, the low for Jan. 3 was 17 in 1979.

"We're not forecasting quite that low, but close," he said. "There's a chance that the temperature in Slidell could drop to 18 or 19 degrees.

Winds blowing out of the north also are expected to produce unusually low tides, a foot or two below normal for coastal waters, he said.

By Friday, a warming trend will have begun, with temperatures rising into the lower 60s under partly cloudy skies. By Saturday night, a chance of rain returns to the area, as lows reach only 60. A chance of showers extends into Monday, with BCS Championship Game fans expected to see temperatures at game time in the mid-60s.